Two-cycle gas engine



Dec. 20, 1932. I E. M. TUCKER 1,891,510

} TWO-CYCLE GAS ENGINE Filed June 23, 1930 4 Sheets-Shet' 1 INVENTOR 22v E.M,TLu-ker TQ }.um ATTORNEY 1932- E. M. TUCKER TWO-CYCLE GAS ENGINE Filed June 23, 1930 4 Sheets-Sheet 2 4 INCVENTORQ EM. Tucker BY @d gyuqsmw ATTORNEY Dec 20, 1932. C E 1,891,510

TWO-CYCLE GAS ENGINE I Filed June 23, 1950 Sheets-Sheet I5 2 7 I r INVENTOR Tucker ATTORN EY Dec. 20, 1932. T ER 1,891,510

TWO-CYCLE GAS ENGINE Filed June 25, 1930 4 Sheets-Sheet 4 j I INVENTOR Patented Dec. 20, 1932 UNITE-D STATE-S PATENTS Mme EMMITT- M. TUCKER; 'OF. 'SAGRAIMIE'N'IO, CALIFORNILuASSIGlNOR T'O' TUCKER DIESEL MOTOR (10;, LTD.; A CORPORATION 'OF-OALIFORNIAY TWO-CYCLE GAS ENGINE.

Application filed June 23',

This invention relates to gas engines, and particularly to one of the so-called well know-n two cycle type.

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compression; and one in which the heated parts are-automatically subjected to a cool- As a result "of these'features an extremely efficient fuel mixtureis attained,- the engine itself is extremely efficient and economical to operate;-it is much easier to attain and hold-- the-desired compression-than is thecase-with the ordinary two cycle engine, and it is also-' easier to keep the engine in a proper relatively cool condition than theusual engine of the.

, high compression type.

A further object of the invention-1s to producea simple and inexpensive deviceandyet one which will be exceedingly ieifective forthe purpose for which it is designed.- These objects I accomplish by means of following specification and claims;

In the drawings similar characters of reference indicate corresponding parts -in -theseveral views:

Fig.-l is a side elevation of my improved engine,-built in. a single cylinder form, show ing the piston in position tO'IGCGIVB'a power impulse.

tion as in- F ig. 1.

Fig. 3 is-a fragmentary sectional planon'a the line 33 of Fig.2.

Fig. 4 is a transverse vertical section of the 'engineshowin'g the piston in a gas dis- 1 charging position.

Fig.5 is a side elevation of the engine, show- The principal objects of my invention areing actionwith the'operation of the engine.

Fig.2 is a fragmentary sectional elevation of the engine with the parts in the same posi-' 1930; Serial no. 463,156;

Referring now more particularly" to the characters of reference on the drawings and-- particular-ly at present to Figs-.1 to 4,-the en-- gme comprises an upper intake and compres-- sion cylinder 1, open on: its lower end, I and a hollow cylindricalhead 2 longitudinally aligned. with said cylinder and disposedjust below saidopen end.- At-this end the cylinder is provided with an annular outwa'rdly pro jecting exhaust manifold 3 I which communicates with the cylinder area all around the same; and having a lateral outlet'l adapted; for connecti'ontoanexhaustpipe of suitable character. Though the cylinder and manifold have been-shown-as separateparts this isfor convenience of manufa'cture' and they may Ice-considered as-a single unit.

Slidably mounted: on the head 2 and so-as to'have a running fit withsaid head and with the-interior of the cylinder (except toward the-upper end of thela'tter where the running-fit i-s-reli'eved) is'a sleeve piston-or cylin der piston 5. which is closedon-its end' be tween" the head-of the cylinderand the adjacent-end of "the head, and is'movable-between these' parts to within close distances of the same. Rings (S -above andibelow the manifold opening and similar rings 7 aboutthe upper end of the head engage-the-outer' such structure and relative arrangement of parts as willfully appear bya perusal of theits'istrokeor adjacent-the head of the'cylinder; The head of' the piston has a "down-x wardly' or'inwardly opening valve 9 ofthepoppet type, -which is normally held .closed'by-j a spring -1'0'. The cylinder head-preferably has a longitudinally adjustable pin 11' which isin the form ofa set screw and is adapted to-engage and positively depress the stemof-the valve if necessary toefie'c-t the-opening of the latter when the pistonis in said position. The head 2 is provided with anignition plug 12 of common character whose points are exposed tothearea A which is 'between'the upper end of the head 2 and the" head of the piston. This. plug .is mounted in a pocket-13 whichis open-to and down one 1 ts outer end for connection to a carbureter,

extends under the head 2 and then upwardly into the same to near the top thereof, being open at its upper end. At the bottom of the head (which is closed) and to oneside of the pipe 15, an outlet passage 16 communicates with a vertical pipe 17 which extends upwardly along one side of the engine and is connected at its upper end to a passage member 18 which in turn communicates with the cylinder 1 on the corresponding side of the engine and adjacent the top of said cylinder. A normally closed poppet valve 19 opening inwardly or toward the cylinder is mounted in the passage 18. V

The length of the piston is such that when at the upper end of its stroke, its lower end projects below the manifold 3 a sufficient distance to afford propersupport for opposed trunnions 20. Said piston at this time of course also still engages the head rings 7 Turnable on the trunnions are the adjacent ends of a forked connecting rod 21 which at its lower end engages the pin of the crank 22 of a crankshaft 23. The throw of the crank is designed so as to cause the piston to be reciprocated through a stroke of sufficient length to move the piston head from adjacent the head of the cylinder to adjacent the upper end. of the head 2. The cylinder and head are maintained rigid and in spaced relation to each otherby side rods 24 which project through and are securely clamped by nuts 25 to base bosses 26 projecting from said members; while said rods extend down to and support the bearings 27 of the crankshaft.

The lower ends of said rods may also serve as the studs for locating and securing the caps of said bearings in place. The particular form of connection between the rods and the cylinder bosses enables said cylinder to be adjusted vertically relative to the head, thereby altering the compression space in said cylinder, as may be desired. The engine as a whole is supported from a suitable foundation by legs 28 which are connected to the rods 24 intermediate the ends of the same. This arrangement is particularly intended for lightengines, larger ones possibly needing a different and more rigid structure.

The head rings 7 and the inner walls of the piston are lubricated by means of an oil passage 29 extending from the ring grooves to the lower end of the head for connection to a pressure feed pipe 30. ,The rings 6 and the outer walls of the piston are lubricated from oil vapors in the fresh mixture which is admitted to the cylinder 1, as is customarily done in two cycle practice.

In operation with the piston positioned as in Fig. 2, the firing and expansion chamber A of the cylinder-piston is filled with acompressed charge, which is exploded by the plug, thus driving the piston upwardly and of course imparting rotation to the crankshaft. lVhen the piston reaches the top of its stroke the ports 8 register with the exhaust manifold and the products of combustion rush out. At the same timethe valve manifold 9 opens, either by engagement with the pin 11 or by reason of the pressure of the fresh charge in the cylinder above the piston, and which has been highly compressed by the upward movement of the piston. The fresh charge rushing into the chamber A of course-positively forces the remainder of the products of combustion into the exhaust manifold and a thorough scavenging of said chamber is thus effected. As soon as the piston starts on its downward stroke the ports 8 move out of register with and shut off the manifold, and the valve 9 closes, and a recompression of the fresh mixture taken into the chamber A, as above stated, now begins. At the same time the downward movement of the piston induces a tendency to vacuum in the cylinder above, causing the valve 19 to open and a rush of fresh mixture to enter the cylinder, to be again compressed upon the subsequent firing stroke and upward movement of the piston. The fact that the cylinder is of course of greater area than the chamber A, and that practically the entire charge from said cylinder is received into the chamber, causes the recompressing action to give the mixture a higher pressure than it had when initially compressed in the cylinder.

The fresh charge being first discharged into the head 2 against the top wall of the same before being delivered to the cylinder, not only exerts a beneficial cooling effect on the Walls of the head, but by absorbing a correspondng amount of heat is delivered into the cylinder 1n a properly preheated condition. This arrangement also causes a thorough mixmg of the air and fuel to be effected before sald mixture is passed to the cylinder; and a further mixing is efiected by reason of the alternating compressing and expanding action to which the mixture is subjected before being finally fired. The piston is readily kept in a cool condition by means of a suitable air blast, without any additional mechanism being necessary, since on every alternate stroke, the piston is exposed for the greater portion of its area to the outside of the cylinder.

In the engine shown in Fig. 5 the cylinder and piston arrangement remains the same as above described, but theyare disposed in inverted relation to the crankshaft 23a. The connecting rod 21a therefore which is connected to the piston 5a extends downwardly past the cylinder 1a to its connection with the crankshaft. Also the tie rods 2401 are placed in position as well as the supporting legs 28a. Otherwise the parts of the engine are unchanged and the movements and functioning of these parts are identical with that described in connection with the first type.

In either case, the piston, being capable of being readily cooled, is not subject to such expansion as is ordinarily the case, and it may therefore have a closer fit with its cooperating parts. This feature, together with the fact that the piston is guided both on the outside and inside, will eliminate piston slap.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

1. In a two-cycle gas engine having a cylinder open on one end, a cylindrical head alined and fixed with and extending beyond the cylinder from the open end thereof, and a sleeve piston slidably engaging the head and cylinder and closed on that end which is with in the cylinder; an ignition plug mounted within the head in a position to fire a charge confined in the piston, and a pocket in and open to one side of the head and in which the outer end of the plug is disposed; the piston being arranged to uncover said pocket when the piston is moved so that its head is adjacent that of the cylinder.

2. In a two-cycle gas engine having a cylinder open on one end, a cylindrical head alined and fixed with and extending beyond the cylinder from the open end thereof, and a sleeve piston slidably engaging the head and cylinder and closed on that end which is within the cylinder; an enclosed chamber formed within the head, a fuel-mixture pipe leading into said chamber and terminating in an open end facing the end of the head which is nearest the head of the piston, and an outlet pipe from the opposite end of the chamber, the cylinder having an intake passage with which said outlet communicates.

3. In a two-cycle gas engine having a cylinder open on one end, a cylindrical head alined and fixed with and extending beyond the cylinder from the open end thereof, anda sleeve piston slidably engaging the head and cylinder and closed on that end which is within the cylinder; one end of the piston projecting at all times in the clear beyond the open end of the cylinder, opposed trunnions projecting outwardly'from said one end of the piston, a crankshaft having a single crank thereon disposed centrally of the axial line of the piston, and a forked connecting rod engaging said crank and the trunnions.

4. In a two-cycle gas engine having a cylinder open on one end, a cylindrical head alined and fixed with and extending beyond the cylinder from the open end thereof, and a sleevepiston slidably engaging the head and cylinder and closed on that end which is within the cylinder, exteriorally located circumferentially spaced elements connected to the cylinder and to the head at the end of the latter furtherest from the cylinder to tie the two together, one end of the piston projecting at all times in the clear beyond the open end of the cylinder, and connecting rod arms engaging said end of the piston on the outside of the same and projecting beyond the head between the elements.

5. In a gas engine having a cylinder open on one end, a cylindrical head alined and fixed with and extending beyond the cylinder from the open end thereof, and a sleeve piston slidably engaging the head and cylinder and closed on that end within the cylinder; a fuel intake passage leading into the cylinder at its closed end, an inwardly opening intake valve in the closed end of the piston, and means to positively open said valve with the movement of the piston to its limit in the direction of closed end of the cylinder.

In testimony whereof Iaflix my signature.

EMMITT M. TUCKER. 

